From: Keir Fraser <keir.fraser@citrix.com>
Date: Thu, 13 Nov 2008 13:03:16 +0000 (+0000)
Subject: x86: Use the shadow-code PT walker from the HAP functions
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14043^2~33
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=49bd5ded4ed1d92696097e4c9d708049c33bddf6;p=xen.git

x86: Use the shadow-code PT walker from the HAP functions

Replace the guts of the HAP pagetable walker with a call to the
newly-commonified walker from the shadow code.  This reduces
duplication, and gives HAP guests proper access control and A/D-bit
setting for memory accesses from the emulator

Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>
---

diff --git a/xen/arch/x86/mm/hap/guest_walk.c b/xen/arch/x86/mm/hap/guest_walk.c
index 62a805750a..425031508d 100644
--- a/xen/arch/x86/mm/hap/guest_walk.c
+++ b/xen/arch/x86/mm/hap/guest_walk.c
@@ -19,160 +19,71 @@
  * Place - Suite 330, Boston, MA 02111-1307 USA.
  */
 
-#include <xen/config.h>
-#include <xen/types.h>
-#include <xen/mm.h>
+
 #include <xen/domain_page.h>
-#include <asm/page.h>
-#include <xen/event.h>
+#include <xen/paging.h>
+#include <xen/config.h>
 #include <xen/sched.h>
-#include <asm/hvm/svm/vmcb.h>
-#include <asm/domain.h>
-#include <asm/paging.h>
-#include <asm/p2m.h>
-#include <asm/hap.h>
-
-#include "private.h"
 
 #define _hap_gva_to_gfn(levels) hap_gva_to_gfn_##levels##level
 #define hap_gva_to_gfn(levels) _hap_gva_to_gfn(levels)
 
-#if GUEST_PAGING_LEVELS > CONFIG_PAGING_LEVELS
+#if GUEST_PAGING_LEVELS <= CONFIG_PAGING_LEVELS
 
-unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
-    struct vcpu *v, unsigned long gva, uint32_t *pfec)
-{
-    gdprintk(XENLOG_ERR,
-             "Guest paging level is greater than host paging level!\n");
-    domain_crash(v->domain);
-    return INVALID_GFN;
-}
-
-#else
-
-#if GUEST_PAGING_LEVELS == 2
-#include "../page-guest32.h"
-#define l1_pgentry_t l1_pgentry_32_t
-#define l2_pgentry_t l2_pgentry_32_t
-#undef l2e_get_flags
-#define l2e_get_flags(x) l2e_get_flags_32(x)
-#undef l1e_get_flags
-#define l1e_get_flags(x) l1e_get_flags_32(x)
-#endif
+#include <asm/guest_pt.h>
 
 unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
     struct vcpu *v, unsigned long gva, uint32_t *pfec)
 {
-    unsigned long gcr3 = v->arch.hvm_vcpu.guest_cr[3];
-    int mode = GUEST_PAGING_LEVELS;
-    int lev, index;
-    paddr_t gpa = 0;
-    unsigned long gpfn, mfn;
+    unsigned long cr3;
+    uint32_t missing;
+    mfn_t top_mfn;
+    void *top_map;
     p2m_type_t p2mt;
-    int success = 1;
+    walk_t gw;
 
-    l1_pgentry_t *l1e;
-    l2_pgentry_t *l2e;
-#if GUEST_PAGING_LEVELS >= 3
-    l3_pgentry_t *l3e;
-#endif
-#if GUEST_PAGING_LEVELS >= 4
-    l4_pgentry_t *l4e;
-#endif
-
-    gpfn = (gcr3 >> PAGE_SHIFT);
-    for ( lev = mode; lev >= 1; lev-- )
+    /* Get the top-level table's MFN */
+    cr3 = v->arch.hvm_vcpu.guest_cr[3];
+    top_mfn = gfn_to_mfn(v->domain, _gfn(cr3 >> PAGE_SHIFT), &p2mt);
+    if ( !p2m_is_ram(p2mt) )
     {
-        mfn = mfn_x(gfn_to_mfn(v->domain, gpfn, &p2mt));
-        if ( !p2m_is_ram(p2mt) )
-        {
-            HAP_PRINTK("bad pfn=0x%lx from gva=0x%lx at lev%d\n", gpfn, gva,
-                       lev);
-            success = 0;
-            break;
-        }
-        ASSERT(mfn_valid(mfn));
-
-        index = (gva >> PT_SHIFT[mode][lev]) & (PT_ENTRIES[mode][lev]-1);
-
-#if GUEST_PAGING_LEVELS >= 4
-        if ( lev == 4 )
-        {
-            l4e = map_domain_page(mfn);
-            if ( !(l4e_get_flags(l4e[index]) & _PAGE_PRESENT) )
-            {
-                HAP_PRINTK("Level 4 entry not present at index = %d\n", index);
-                success = 0;
-            }
-            gpfn = l4e_get_pfn(l4e[index]);
-            unmap_domain_page(l4e);
-        }
-#endif
+        pfec[0] &= ~PFEC_page_present;
+        return INVALID_GFN;
+    }
 
-#if GUEST_PAGING_LEVELS >= 3
-        if ( lev == 3 )
-        {
-            l3e = map_domain_page(mfn);
+    /* Map the top-level table and call the tree-walker */
+    ASSERT(mfn_valid(mfn_x(top_mfn)));
+    top_map = map_domain_page(mfn_x(top_mfn));
 #if GUEST_PAGING_LEVELS == 3
-            index += ((gcr3 >> 5) & 127) * 4;
-#endif
-            if ( !(l3e_get_flags(l3e[index]) & _PAGE_PRESENT) )
-            {
-                HAP_PRINTK("Level 3 entry not present at index = %d\n", index);
-                success = 0;
-            }
-            gpfn = l3e_get_pfn(l3e[index]);
-            unmap_domain_page(l3e);
-        }
+    top_map += (cr3 & ~(PAGE_MASK | 31));
 #endif
+    missing = guest_walk_tables(v, gva, &gw, pfec[0], top_mfn, top_map);
+    unmap_domain_page(top_map);
+
+    /* Interpret the answer */
+    if ( missing == 0 ) 
+        return gfn_x(guest_l1e_get_gfn(gw.l1e));
+    
+    if ( missing & _PAGE_PRESENT )
+        pfec[0] &= ~PFEC_page_present;
+    
+    return INVALID_GFN;
+}
 
-        if ( lev == 2 )
-        {
-            l2e = map_domain_page(mfn);
-            if ( !(l2e_get_flags(l2e[index]) & _PAGE_PRESENT) )
-            {
-                HAP_PRINTK("Level 2 entry not present at index = %d\n", index);
-                success = 0;
-            }
-
-            if ( l2e_get_flags(l2e[index]) & _PAGE_PSE )
-            {
-                paddr_t mask = ((paddr_t)1 << PT_SHIFT[mode][2]) - 1;
-                HAP_PRINTK("guest page table is PSE\n");
-                gpa = (l2e_get_intpte(l2e[index]) & ~mask) + (gva & mask);
-                unmap_domain_page(l2e);
-                break; /* last level page table, jump out from here */
-            }
-
-            gpfn = l2e_get_pfn(l2e[index]);
-            unmap_domain_page(l2e);
-        }
-
-        if ( lev == 1 )
-        {
-            l1e = map_domain_page(mfn);
-            if ( !(l1e_get_flags(l1e[index]) & _PAGE_PRESENT) )
-            {
-                HAP_PRINTK("Level 1 entry not present at index = %d\n", index);
-                success = 0;
-            }
-            gpfn = l1e_get_pfn(l1e[index]);
-            gpa = (l1e_get_intpte(l1e[index]) & PAGE_MASK) + (gva &~PAGE_MASK);
-            unmap_domain_page(l1e);
-        }
-
-        if ( success != 1 ) /* error happened, jump out */
-            break;
-    }
-
-    gpa &= PADDR_MASK;
-    HAP_PRINTK("success = %d, gva = %lx, gpa = %lx\n", success, gva, gpa);
+#else
 
-    return (!success ? INVALID_GFN : ((paddr_t)gpa >> PAGE_SHIFT));
+unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
+    struct vcpu *v, unsigned long gva, uint32_t *pfec)
+{
+    gdprintk(XENLOG_ERR,
+             "Guest paging level is greater than host paging level!\n");
+    domain_crash(v->domain);
+    return INVALID_GFN;
 }
 
 #endif
 
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/x86/mm/hap/private.h b/xen/arch/x86/mm/hap/private.h
index 00bed88db4..7b06e7df63 100644
--- a/xen/arch/x86/mm/hap/private.h
+++ b/xen/arch/x86/mm/hap/private.h
@@ -20,9 +20,6 @@
 #ifndef __HAP_PRIVATE_H__
 #define __HAP_PRIVATE_H__
 
-#include <asm/flushtlb.h>
-#include <asm/hvm/support.h>
-
 /********************************************/
 /*          GUEST TRANSLATION FUNCS         */
 /********************************************/
@@ -33,36 +30,5 @@ unsigned long hap_gva_to_gfn_3level(struct vcpu *v, unsigned long gva,
 unsigned long hap_gva_to_gfn_4level(struct vcpu *v, unsigned long gva,
                                     uint32_t *pfec);
 
-/********************************************/
-/*            MISC DEFINITIONS              */
-/********************************************/
-
-/* PT_SHIFT describes the amount by which a virtual address is shifted right 
- * to right justify the portion to be used for indexing into a page 
- * table, given the guest memory model (i.e. number of levels) and the level 
- * of the page table being accessed. The idea is from Virtual Iron's code.
- */
-static const int PT_SHIFT[][5] =
-  {   /*     ------  level ------           nr_levels  */
-    /*         1     2     3     4                   */
-    {    0,    0,    0,    0,    0},   /* 0 not used */
-    {    0,    0,    0,    0,    0},   /* 1 not used */
-    {    0,   12,   22,    0,    0},   /* 2  */
-    {    0,   12,   21,   30,    0},   /* 3  */
-    {    0,   12,   21,   30,   39}    /* 4  */
-  };
-
-/* PT_ENTRIES describes the number of entries in a page table, given the 
- * memory model (i.e. number of levels) and the level of the page table 
- * being considered. This idea from Virtual Iron's shadow code*/
-static const int PT_ENTRIES[][5] =
-  {   /*     ------  level ------           nr_levels  */
-    /*         1     2     3     4                   */
-    {    0,    0,    0,    0,    0},   /* 0 not used */
-    {    0,    0,    0,    0,    0},   /* 1 not used */
-    {    0, 1024, 1024,    0,    0},   /* 2  */
-    {    0,  512,  512,    4,    0},   /* 3  */
-    {    0,  512,  512,  512,  512}    /* 4  */
-  };
 
 #endif /* __SVM_NPT_H__ */
diff --git a/xen/arch/x86/mm/page-guest32.h b/xen/arch/x86/mm/page-guest32.h
deleted file mode 100644
index 5d333bd91b..0000000000
--- a/xen/arch/x86/mm/page-guest32.h
+++ /dev/null
@@ -1,100 +0,0 @@
-
-#ifndef __X86_PAGE_GUEST_H__
-#define __X86_PAGE_GUEST_H__
-
-#ifndef __ASSEMBLY__
-# include <asm/types.h>
-#endif
-
-#define PAGETABLE_ORDER_32         10
-#define L1_PAGETABLE_ENTRIES_32    (1<<PAGETABLE_ORDER_32)
-#define L2_PAGETABLE_ENTRIES_32    (1<<PAGETABLE_ORDER_32)
-#define ROOT_PAGETABLE_ENTRIES_32  L2_PAGETABLE_ENTRIES_32
-
-
-#define L1_PAGETABLE_SHIFT_32 12
-#define L2_PAGETABLE_SHIFT_32 22
-
-/* Extract flags into 12-bit integer, or turn 12-bit flags into a pte mask. */
-
-#ifndef __ASSEMBLY__
-
-typedef u32 intpte_32_t;
-
-typedef struct { intpte_32_t l1; } l1_pgentry_32_t;
-typedef struct { intpte_32_t l2; } l2_pgentry_32_t;
-typedef l2_pgentry_t root_pgentry_32_t;
-#endif
-
-#define get_pte_flags_32(x) ((u32)(x) & 0xFFF)
-#define put_pte_flags_32(x) ((intpte_32_t)(x))
-
-/* Get pte access flags (unsigned int). */
-#define l1e_get_flags_32(x)           (get_pte_flags_32((x).l1))
-#define l2e_get_flags_32(x)           (get_pte_flags_32((x).l2))
-
-#define l1e_get_paddr_32(x)           \
-    ((paddr_t)(((x).l1 & (PADDR_MASK&PAGE_MASK))))
-#define l2e_get_paddr_32(x)           \
-    ((paddr_t)(((x).l2 & (PADDR_MASK&PAGE_MASK))))
-
-/* Construct an empty pte. */
-#define l1e_empty_32()                ((l1_pgentry_32_t) { 0 })
-#define l2e_empty_32()                ((l2_pgentry_32_t) { 0 })
-
-/* Construct a pte from a pfn and access flags. */
-#define l1e_from_pfn_32(pfn, flags)   \
-    ((l1_pgentry_32_t) { ((intpte_32_t)(pfn) << PAGE_SHIFT) | put_pte_flags_32(flags) })
-#define l2e_from_pfn_32(pfn, flags)   \
-    ((l2_pgentry_32_t) { ((intpte_32_t)(pfn) << PAGE_SHIFT) | put_pte_flags_32(flags) })
-
-/* Construct a pte from a physical address and access flags. */
-#ifndef __ASSEMBLY__
-static inline l1_pgentry_32_t l1e_from_paddr_32(paddr_t pa, unsigned int flags)
-{
-    ASSERT((pa & ~(PADDR_MASK & PAGE_MASK)) == 0);
-    return (l1_pgentry_32_t) { pa | put_pte_flags_32(flags) };
-}
-static inline l2_pgentry_32_t l2e_from_paddr_32(paddr_t pa, unsigned int flags)
-{
-    ASSERT((pa & ~(PADDR_MASK & PAGE_MASK)) == 0);
-    return (l2_pgentry_32_t) { pa | put_pte_flags_32(flags) };
-}
-#endif /* !__ASSEMBLY__ */
-
-
-/* Construct a pte from a page pointer and access flags. */
-#define l1e_from_page_32(page, flags) (l1e_from_pfn_32(page_to_mfn(page),(flags)))
-#define l2e_from_page_32(page, flags) (l2e_from_pfn_32(page_to_mfn(page),(flags)))
-
-/* Add extra flags to an existing pte. */
-#define l1e_add_flags_32(x, flags)    ((x).l1 |= put_pte_flags_32(flags))
-#define l2e_add_flags_32(x, flags)    ((x).l2 |= put_pte_flags_32(flags))
-
-/* Remove flags from an existing pte. */
-#define l1e_remove_flags_32(x, flags) ((x).l1 &= ~put_pte_flags_32(flags))
-#define l2e_remove_flags_32(x, flags) ((x).l2 &= ~put_pte_flags_32(flags))
-
-/* Check if a pte's page mapping or significant access flags have changed. */
-#define l1e_has_changed_32(x,y,flags) \
-    ( !!(((x).l1 ^ (y).l1) & ((PADDR_MASK&PAGE_MASK)|put_pte_flags_32(flags))) )
-#define l2e_has_changed_32(x,y,flags) \
-    ( !!(((x).l2 ^ (y).l2) & ((PADDR_MASK&PAGE_MASK)|put_pte_flags_32(flags))) )
-
-/* Given a virtual address, get an entry offset into a page table. */
-#define l1_table_offset_32(a)         \
-    (((a) >> L1_PAGETABLE_SHIFT_32) & (L1_PAGETABLE_ENTRIES_32 - 1))
-#define l2_table_offset_32(a)         \
-    (((a) >> L2_PAGETABLE_SHIFT_32) & (L2_PAGETABLE_ENTRIES_32 - 1))
-
-#endif /* __X86_PAGE_GUEST_H__ */
-
-/*
- * Local variables:
- * mode: C
- * c-set-style: "BSD"
- * c-basic-offset: 4
- * tab-width: 4
- * indent-tabs-mode: nil
- * End:
- */